Background - Solar energetic particles (SEP)
associated with coronal mass ejections or CMEs occur with little or no advance
warning, and are often accompanied by high-energy ions that pose severe
radiation hazards for humans and hardware in space. Recently, composition
measurements from NASA's Advanced Composition Explorer (ACE) spacecraft have
provided compelling evidence that the source material for such CME-related SEP
events originates from the suprathermal tail between approximately 2
to 100 keV/nucleon rather than from the more abundant solar wind peak near
approximately 1 to 2 keV/nucleon. Presently, however, properties of the
suprathermal tail are not well known mainly because current solar wind
instruments are relatively insensitive in the approximately 2 to 100 keV/nucleon
energy range, while energetic particle instruments use solid-state detectors
with high ( approximately 50 to 100 keV) lower-energy thresholds. Thus, these
new findings have inspired numerous scientific investigations and competing
hardware efforts to participate in a frantic race to be the first to measure and
explore the uncharted suprathermal energy region. Furthermore, at present the
ionic charge state and isotopic composition of the accelerated ion populations
in the approximately 0.1 to 10 MeV/nucleon energy range are typically obtained
by two or more large instruments on the same spacecraft. For example, SEPICA and
ULEIS on ACE collectively weigh about 60 kg. However, such large instruments are
highly unlikely to fly on future NASA missions.

This project will investigate the feasibility of an
innovative concept for a single lightweight (less than approximately 15 kg)
instrument that can measure the ionic charge state, isotopic, and elemental
abundances of both the suprathermal and the energetic particle populations in
the heliosphere. A single instrument that makes detailed composition
measurements of the hitherto unexplored suprathermal tail between approximately
8 to 100 keV/nucleon and of the energetic ions between approximately 0.1 to 10
MeV/nucleon will provide a much-needed breakthrough in making charged particle
measurements in the heliosphere. SwRI's new instrument  Advanced Mass and Ionic
Charge Composition Experiment (AMICCE)  will easily meet the scientific
requirements of three or more separate state-of-the-art instruments, and will
therefore provide enough flexibility to remain within the stringent payload
allocation for a variety of upcoming NASA and European heliospheric missions.

Approach - The project was divided into four
tasks:

Optimization and simulations of the
electrostatic analyzer (ESA)

Optimization and simulations of the
Time-of-Flight (TOF)

Design, fabrication, and testing of the ESA
prototype

Publication of results in a scientific refereed
journal

Accomplishments - The project team
successfully modeled, designed, built, and tested a laboratory prototype for an
innovative electrostatic analyzer (ESA) for AMICCE. The team also finished
simulations and optimized the TOF section of the instrument, and designed and
ordered a collimator for the ESA. Results are being organized for publication in
a peer-reviewed scientific journal.

The work resulting from this internal research effort
has also enabled SwRI to successfully propose for a Supporting Research and
Technology (SR&T) grant from NASA to further develop the concept over a period
of three years. The ESA-collimator assembly will be
tested using the funding from this project. An instrument paper demonstrating
the proof-of-concept in conjunction with further development work from the NASA
SR&T grant will increase the technology readiness level of AMICCE and be ready
for the next announcements of opportunity from NASA for future missions such as
the Inner Heliospheric Sentinels.